^ OF ARTS AND SCIENCES. 107 



,'.-.%.■ 





VII. 



CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY 



OF THE MUSEUxM OF COMPARATIVE ZOOLOGY 



AT HARVARD COLLEGE. 



No. VII. — DESCRIPTIONS OF NEW SPECIES OF CA3f- 

 BARUS; TO WHICH IS ADDED A SYNONYMICAL 

 LIST OF THE KNOWN SPECIES OF GAMBARUS 

 AND ASTACUS. 



By Walter Faxon. 



Communicated November 12th, 1884. 



Sixteen years have elapsed since the North American Crayfishes 

 were revised by Dr. Hagen.* In the mean while a large amount of 

 new material has accumulated in the Museum of Comparative Zoology. 

 On examination, this material revealed so many new forms, and shed 

 so much light on the variability and geographical distribution of these 

 animals, that it seemed desirable to subject the group anew to a criti- 

 cal revision. With this in view I have examined all the collections 

 accessible, including those belonging to the Museum of Comparative 

 Zoology, the Boston Society of Natural History, the Peabody 

 Academy of Science at Salem, Mass., the Academy of Natural Sci- 

 ences of Philadelphia, the United States National Museum at Wash- 

 ington, D. C, Yale College, New Haven, Conn., Bowdoin College, 

 Brunswick, Me., and Butler University, Irvington, Ind., together with 

 the private collections of Mr. P. R. Uhler of Baltimore, Md., Prof. 

 O. P. Hay of Irvington, Ind., Prof L. A. Lee of Brunswick, IMe., Prof. 

 A. S. Packard of Providence, R. I,, Prof. D. S. Jordan of Washing- 

 ton, D. C, Mr. R. S. Tarr of Gloucester, Mass., Dr. C. Hart Merriam 

 of Locust Grove, N. Y., and Prof B. F. Koons of Mansfield, Conn. 

 Only through the kind offices of the curators of these collections was 

 a thorough revision of this difficult group possible. I have now ready 

 for the press the first part of a revision of the Astacina, embracing 



* 111. Cat. Mus. Comp. Zool., No. III. This monograph was finished in 

 1868, although not published until 1870. 



